CVE-2026-74973: mozilla firefox Race Condition
CVSS: 4.2v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-74973DEBIAN-CVE-2026-74973
Published 18-08-2026Last modified 18-08-2026
Vulnerability summary
CVE-2026-74973 is a medium (CVSS 4.2) Race Condition vulnerability in mozilla firefox. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 11.2% of scored vulnerabilities.
CVSS score
4.2/10
010
Medium · v3.1 (CVE.org)EPSS score
0.21%
0%100%
Low · +0.04 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 37 · Related 14MGASA-2026-0345MGASA-2026-0346OPENSUSE-SU-2026:11546-1OPENSUSE-SU-2026:11558-1OPENSUSE-SU-2026:11580-1OPENSUSE-SU-2026:21594-1OPENSUSE-SU-2026:21713-1RHSA-2026:58897RHSA-2026:58898RHSA-2026:58899RHSA-2026:64813RHSA-2026:64814RHSA-2026:65103RHSA-2026:65105RHSA-2026:65110RHSA-2026:65111RHSA-2026:65158RHSA-2026:65159RHSA-2026:65160RHSA-2026:65442RHSA-2026:65633RHSA-2026:65669RHSA-2026:65670RHSA-2026:65757RHSA-2026:65764RHSA-2026:65765RHSA-2026:65766RHSA-2026:65888SUSE-SU-2026:23304-1SUSE-SU-2026:23411-1SUSE-SU-2026:23590-1SUSE-SU-2026:3658-1SUSE-SU-2026:3683-1SUSE-SU-2026:3897-1SUSE-SU-2026:4140-1SUSE-SU-2026:4156-1SUSE-SU-2026:4268-1
Timeline
- 18-08-2026PublishedVulnerability first disclosed.
- 18-08-2026Last modifiedVulnerability information updated.
Description
Race condition, use-after-free in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
CVSS metrics
4 scores · 4 sources · 1 versionMedium 4.2Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:NSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated4.2MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
- OSV · DebianEcosystem advisory · calculated4.2MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
- NVDNIST4.2MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.21%
Chance of exploitation in the next 30 days
Percentile
11%
Versus all other CVEs
30-day change
+0.04 pp
From 0.18% on 19-09-2026
19-09-202619-10-2026
EPSS score0.21%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Affected systems
Ubuntu8 products
- mozjs102All versions (No fix recorded)
- mozjs115All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
Debian2 products
- firefox-esr< 140.14.0esr-1~deb12u1 | < 140.14.0esr-1~deb13u1 | < 140.14.0esr-2
- thunderbird< 1:140.14.0esr-1~deb12u1 | < 1:140.14.0esr-1~deb13u1 | < 1:140.14.0esr-1
Mozilla2 products
- firefox< 115.39.0 | ≥ 116.0, < 140.14.0 | ≥ 141.0, < 153.1.0
- thunderbird< 140.14.0 | ≥ 141.0, < 153.1.0
3 vendors · 12 products
References
14 links- bugzilla.mozilla.org/show_bug.cgi?id=2060357Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-74/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-75/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-76/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-77/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-78/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-79/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-80/Vendor Advisory
