Mozilla Foundation Security Advisory 2026-120

Security Vulnerabilities fixed in Firefox ESR 153.6

Announced
October 27, 2026
Impact
high
Products
Firefox ESR
Fixed in
  • Firefox ESR 153.6

Note: We have changed how we publish advisories. We no longer roll all internally identified memory safety vulnerabilities into a single CVE and are now issuing an advisory for every individual bug.

#CVE-2026-117860: Same-origin policy bypass in the DOM: Navigation component

Reporter
satyamasd
Impact
high
References

#CVE-2026-117861: Sandbox escape in the DOM: Navigation component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117862: Privilege escalation due to incorrect boundary conditions in the Networking component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117863: Information disclosure due to uninitialized memory in the Audio/Video component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117864: Sandbox escape in the Form Manager component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117865: Use-after-free in the JavaScript: GC component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117866: Privilege escalation due to use-after-free in the Graphics: Canvas2D component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117867: Use-after-free in the Layout component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117868: Sandbox escape in the DOM: Networking component

Reporter
Yaqoub Aldurayhim
Impact
high
References

#CVE-2026-117869: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117870: Use-after-free in the JavaScript Engine component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117871: Invalid pointer in the Graphics component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117872: Use-after-free in the JavaScript: Standard Library component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117873: Incorrect boundary conditions in the Audio/Video: Playback component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117874: Use-after-free in the Internationalization component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117875: Use-after-free in the Layout: Scrolling and Overflow component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117876: Use-after-free in the Layout: Text and Fonts component

Reporter
Amy Burnett of OpenAI
Impact
high
References

#CVE-2026-117877: Use-after-free in the Layout: Text and Fonts component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117878: Other issue, use-after-free in the Storage: IndexedDB component

Reporter
Amy Burnett of OpenAI
Impact
high
References

#CVE-2026-117879: Incorrect boundary conditions in the Layout: Tables component

Reporter
Amy Burnett of OpenAI
Impact
high
References

#CVE-2026-117880: Use-after-free in the XML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117881: Use-after-free in the DOM: Core & HTML component

Reporter
Amy Burnett of OpenAI
Impact
high
References

#CVE-2026-117882: Use-after-free in the Layout component

Reporter
Amy Burnett of OpenAI
Impact
high
References

#CVE-2026-117883: Use-after-free in the DOM: HTML Parser component

Reporter
Amy Burnett of OpenAI
Impact
high
References

#CVE-2026-117884: Use-after-free in the Networking component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117885: Use-after-free in the Layout: Grid component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117886: Incorrect boundary conditions in the Graphics: Text component

Reporter
tsui
Impact
high
References

#CVE-2026-117887: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117888: Uninitialized memory in the Graphics: Canvas2D component

Reporter
Minseong Kim
Impact
high
References

#CVE-2026-117889: Incorrect boundary conditions in the JavaScript Engine component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117890: JIT miscompilation in the JavaScript Engine: JIT component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117891: Use-after-free in the JavaScript Engine: JIT component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117892: Privilege escalation due to use-after-free in the WebRTC: Networking component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117893: Incorrect boundary conditions in the Security: PSM component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117894: Incorrect boundary conditions in the WebRTC: Signaling component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117895: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117896: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117897: Incorrect boundary conditions in the Layout: Tables component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117898: Use-after-free in the JavaScript Engine: JIT component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117899: Use-after-free in the Networking: HTTP component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117900: Use-after-free in the DOM: Editor component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117901: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117902: Use-after-free in the Layout: Text and Fonts component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117903: Use-after-free in the Audio/Video component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117904: Use-after-free in the JavaScript: GC component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117905: Use-after-free in the Audio/Video: Playback component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117906: Use-after-free in the CSS Parsing and Computation component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117907: Use-after-free in the Networking component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117908: Use-after-free in the Graphics: ImageLib component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117909: Use-after-free in the JavaScript: GC component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117910: Invalid pointer in the JavaScript Engine component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117911: Use-after-free in the Audio/Video: Playback component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117912: Same-origin policy bypass in the CSS Parsing and Computation component

Reporter
Takashi Suzuki
Impact
high
References

#CVE-2026-117913: Use-after-free in the SVG component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117914: Use-after-free in the SVG component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117915: Incorrect boundary conditions in the Layout: Block and Inline component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117916: Use-after-free in the XSLT component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117917: Invalid pointer in the Graphics: WebRender component

Reporter
Nguyen Tuan Hung
Impact
high
References

#CVE-2026-117918: Use-after-free in the Graphics: Canvas2D component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117919: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117920: Use-after-free in the DOM: HTML Parser component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117921: Use-after-free in the CSS Parsing and Computation component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117922: Use-after-free in the Networking: WebSockets component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117923: Use-after-free in the Audio/Video component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117924: Use-after-free in the XSLT component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117925: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117926: Incorrect boundary conditions in the SVG component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117927: Use-after-free in the SVG component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117928: Same-origin policy bypass in the CSS Parsing and Computation component

Reporter
Minseong Kim
Impact
high
References

#CVE-2026-117929: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
high
References

#CVE-2026-117930: Use-after-free in the DOM: Bindings (WebIDL) component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117931: Use-after-free in the DOM: Events component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117932: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117933: Frame poisoning in the CSS Parsing and Computation component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117934: Use-after-free in the Layout component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117935: Use-after-free in the DOM: Bindings (WebIDL) component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117936: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117937: Invalid pointer in the JavaScript Engine component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117938: Use-after-free in the Layout component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117939: Use-after-free in the XML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117940: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117941: Use-after-free in the DOM: CSS Object Model component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117942: Incorrect boundary conditions in the JavaScript Engine: JIT component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117943: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117944: Use-after-free in the Layout component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117945: Incorrect boundary conditions in the XML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117946: Incorrect boundary conditions in the JavaScript Engine component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117947: Use-after-free in the XML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117948: Use-after-free in the SVG component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117949: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117950: Incorrect boundary conditions in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117951: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117952: Uninitialized memory in the Networking component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117953: Use-after-free in the DOM: Core & HTML component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117954: Use-after-free in the Layout: Positioned component

Reporter
OpenAI Codex Security (kylebot)
Impact
high
References

#CVE-2026-117955: JIT miscompilation in the JavaScript: WebAssembly component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-100801: Privilege escalation in the DLL Services component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117956: Invalid pointer in the Nimbus Desktop Client component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117957: Cryptographic issue in the WebRTC: Networking component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117958: Site isolation issue in the Networking: HTTP component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117959: Site isolation issue in the DOM: Service Workers component

Reporter
Muhammad Ali
Impact
moderate
References

#CVE-2026-117960: Spoofing issue in the DOM: Core & HTML component

Reporter
Mohamed Mbarek
Impact
moderate
References

#CVE-2026-117961: Incorrect boundary conditions in the Layout: Text and Fonts component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117962: Sandbox escape due to incorrect boundary conditions in the Storage: Quota Manager component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117963: Incorrect boundary conditions in the DOM: Service Workers component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117964: Use-after-free in the Panning and Zooming component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117965: Same-origin policy bypass in the Address Bar component

Reporter
Takashi Suzuki
Impact
moderate
References

#CVE-2026-117966: Site isolation issue in the Networking: HTTP component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117967: Mitigation bypass in the DOM: Security component

Reporter
Nguyen Tuan Hung
Impact
moderate
References

#CVE-2026-117968: Use-after-free in the DOM: Core & HTML component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117969: Invalid pointer in the JavaScript Engine: JIT component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117970: Race condition in the Disability Access APIs component

Reporter
Nguyen Thanh Nguyen
Impact
moderate
References

#CVE-2026-117971: Sandbox escape due to use-after-free in the Print Preview component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117972: Use-after-free in the Graphics component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117973: Use-after-free in the Networking: DNS component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117974: Use-after-free in the XML component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117975: Sandbox escape due to invalid pointer in the Graphics: WebRender component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117976: Site isolation issue in the DOM: Navigation component

Reporter
Shu Takahashi of Velcore Consulting Inc.
Impact
moderate
References

#CVE-2026-117977: Other issue in the Console component

Reporter
quanhx
Impact
moderate
References

#CVE-2026-117978: Incorrect boundary conditions in the Graphics component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117979: Incorrect boundary conditions in the Graphics: WebRender component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117980: Use-after-free in the Graphics component

Reporter
Massimo Palozzi
Impact
moderate
References

#CVE-2026-117981: Privilege escalation in the Toolkit component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117982: Invalid pointer in the JavaScript Engine: JIT component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117983: Use-after-free in the Graphics component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117984: Incorrect boundary conditions in the Layout: Scrolling and Overflow component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117985: Sandbox escape due to use-after-free in the Graphics component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117986: Use-after-free in the Graphics component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117987: Use-after-free in the Graphics component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117988: Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117989: Use-after-free in the Graphics component

Reporter
Nguyen Tuan Hung
Impact
moderate
References

#CVE-2026-117990: Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117991: Incorrect boundary conditions in the Layout: Text and Fonts component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117992: Information disclosure in the CSS Parsing and Computation component

Reporter
Takashi Suzuki
Impact
moderate
References

#CVE-2026-117993: Integer overflow in the Graphics: Text component

Reporter
5up3rh3i
Impact
moderate
References

#CVE-2026-117994: Use-after-free in the JavaScript: GC component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117995: Privilege escalation in the DOM: UI Events & Focus Handling component

Reporter
haruka yamazaki
Impact
moderate
References

#CVE-2026-117996: Incorrect boundary conditions in the WebRTC component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117997: Sandbox escape due to use-after-free in the Widget component

Reporter
Mozilla
Impact
moderate
References

#CVE-2026-117998: Mitigation bypass in the DOM: Push Subscriptions component

Reporter
Ibuki Sato
Impact
low
References

#CVE-2026-117999: Race condition in the IPC component

Reporter
Mozilla
Impact
low
References

#CVE-2026-118000: Information disclosure in the Networking: HTTP component

Reporter
Mozilla
Impact
low
References

#CVE-2026-118002: Information disclosure due to race condition in the Networking component

Reporter
Abdulrahman Alzahrani
Impact
low
References

#CVE-2026-118003: Information disclosure in the Networking: DNS component

Reporter
eldjiikgull
Impact
low
References

#CVE-2026-118004: Incorrect boundary conditions in the CSS Transitions and Animations component

Reporter
Mozilla
Impact
low
References