CVE-2025-54574: squid-cache squid Heap-based Buffer Overflow
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2025-54574DEBIAN-CVE-2025-54574
Published 01-08-2025Last modified 05-11-2025
Vulnerability summary
CVE-2025-54574 is a critical (CVSS 9.8) Heap-based Buffer Overflow vulnerability in squid-cache squid. EPSS estimates a 23.51% chance of exploitation in the next 30 days, higher than 97.7% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (NVD)EPSS score
23.51%
0%100%
High · +0.84 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 11Timeline
- 01-08-2025PublishedVulnerability first disclosed.
- 05-11-2025Last modifiedVulnerability information updated.
Description
Squid is a caching proxy for the Web. In versions 6.3 and below, Squid is vulnerable to a heap buffer overflow and possible remote code execution attack when processing URN due to incorrect buffer management. This has been fixed in version 6.4. To work around this issue, disable URN access permissions.
CVSS metrics
4 scores · 4 sources · 1 versionCritical 9.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSources4 sources · 9.3–9.8
- CVE.orgCNA9.3CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
23.51%
Chance of exploitation in the next 30 days
Percentile
98%
Versus all other CVEs
30-day change
+0.84 pp
From 22.67% on 18-09-2026
18-09-202618-10-2026
EPSS score23.51%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Ubuntu2 products
- squid< 4.10-1ubuntu1.12 | < 5.7-0ubuntu0.22.04.4
- squid3All versions (No fix recorded)
Debian1 product
- squid< 5.7-2+deb12u3 | < 6.5-1
Squid-cache1 product
- squid< 6.4
3 vendors · 4 products
References
8 links- github.com/squid-cache/squid/security/advisories/GHSA-w4gv-vw3f-29g3X Refsource CONFIRMREPORTMitigationPatchVendor Advisory
